Multi-layer cross-bottom bag



Feb. 28, 1967 KARL-HEINZ HONSEL. 3,306,522

MULTI -LAYER CROSS -BO'ITOM BAG Filed March 10, 1966 5 sheets-sheet 1 5y iif 1 5 Sheets-Sheet 2 In Ven far: KA/EA-Hf/A/Z 4045a WW KARL-HEINZ HONSEL MULTI-LAYER CROSS-BOTTOM BAG Feb. 28, 1967 Filed March 10. 1966 Feb. 28, 1967 KARL-HEINZ HONSEL MULTI-LAYER CROSS-BOTTOM BAG 5 Sheets-Shee Filed March 10, 1966 Fig.6

KARL-HEINZ HONSEL 35%,522

MULTIrL/XYER CROSS-BOTTOM BAG Feb. 23, 1987 5 Sheets-Sheet 4 Filed March 10, 1966 Feb. 28, 1967 KARL-HEINZ HONSEL 3,306,522

MULTI-LAYER CROSs-BOTTOM BAG Filed March 16. 1966 5 Sheets-Shee s Fig. I!

Fig. I?

Fig. I3

In ventor: KA/PA -H f/O/VSZZ 3,306,522 Patented Feb. 28, 1967 3,306,522 MULTI-LAYER CROSS-BOTTOM BAG Karl-Heinz Honsel, Bielefeld, Germany, assignor to Erwin Behn Verpackungsbedarf G.m.b.H., Krefeld, Germany, a firm Filed Mar. 10, 1966, Ser. No. 533,160 Claims priority, application Germany, Mar. 17, 1965, B 81,024 7 Claims. (Cl. 229-55) The invention relates to paper bags such as crossbottom bags and, more particularly, to cross-bottom bags made in several layers which comprise an outer layer, an intermediate layer, and an inner layer.

Multi-layer crossabottom bags made of paper or the like are known, where for forming the bottom corner flaps are provided one each continuous with each of the triangular inward corner folds for gluing onto the lateral folds or pleats after turning them over, for the forming of which flaps incisions are provided which, starting at the edges of the tubular cut off sections, extend in the direction of the tubular section. In these cross-bottom bags the corner flaps which are formed from the tubular section and must be glued from the top onto the turned over side pleats, are staggered at their free ends in the superimposed layers of the bag through cut out portions.

In this arrangement and construction of the corner flaps a powder-proof bottom closure cannot be obtained at the ends proximate the corner fold of the incisions forming the individual corner flaps and defining their lateral limits.

In view of this the invention is based on the problem of forming multi-layer cross-bottom bags where corner flaps join the corner inward folds, in such a manner that with the aid of these corner flaps a bottom is formed which is absolutely sealed so that it is proof for powdered or hygroscopic material. It is intended that particularly at the ends adjacent the corner fold the incisions forming the corner flaps, especially at the incisions of the innermost layer, a closure is formed which reliably closes that end, so that the corner flaps create an air-tight or substantially air-tight closure.

Accordingly, the invention resides in the first place in that the layers of the end flaps and at the two edges formed by the longitudinal incisions are staggered positively from the inside toward the outside.

By virtue of this measure the opening to be closed by the corner flap which is formed at the lateral ends of the side folds, is securely covered at the sides by the staggering of the overlapping edges of the outer layers of the corner flap. This means that the ends proximate the corner fold of the incisions forming the corner flaps are covered at the innermost layer toward the side by staggered edges of the corner flap layers disposed farther out.

In order to achieve the lateral sealing at the locations described in an optimal manner, the invention furthermore provides that the corner flap is provided with at least one adhesive strip that extends from the one edge of the outer layer to the oppositely disposed edge of the same layer of the corner flap along the edge of the opening, by means of which the corner flap end adjacent the corner fold is glued upon the side folds in a sealing manner. The adhesive strip in this connection extends preferably to one or both lateral folds or pleats, i.e. from the corner flap of the edge of the opening onto the lateral folds or pleats.

For improvement of the seal of the opening between corner flaps and side pleats, a welded seam can be applied parallel to the edge of the opening, which seal may be produced, for example, by supersonic waves, and connects the inner layer of the corner fold and the lateral pleats V linearly with one another.

As a further development of the subject of the invention, it is proposed that the inner, or preferably the two inner layers of the inner flap is folded about the edge of the opening, i.e., the transverse edge of the side folds or pleats are turned over and glued together therewith. In this connection the end remote from the corner fold is once more subjected to a folding about the transverse edge of the corner fold. The opening edge here means the connecting line of the ends of the incisions of the corner flaps adjacent the corner fold. The said measure provides particularly in connection with the folding of the two innermost layers against one another that are staggered at their lateral edges, that an additional seal is obtained at the opening edge with respect to the incision end of the inner corner flap layer. The outermost corner flap layers again glue over the location mentioned at the end of the opening edge which is to be sealed.

In accordance with the invention, it is also possible to obtain a seal of this unsafe location in the bottom closure in that at the two end folds of the bottom with closed side folds or pleats, but while the corner flaps still extend outwardly, corner strips are provided, the length of which corresponds to the Width of the outer corner flap layer, and the width of which corresponds to the region approximately between the transverse edge of the corner fold and the free end of the corner flap. -It is also possible to replace the two cover strips required for a bottom by a throughgoin'g cover leaf of corresponding length.

Further objects and advantages of the invention will become apparent from the following description with reference to the drawings which illustrate embodiments of the invention and in which:

FIG. 1 shows in plan view a multi-layer tubular section with the staggering of the individual layers of paper relative 'to one another;

FIG. 2 shows the tubular section in accordance with FIG. 1 with the cross-bottom folded over;

j FIG. 3 shows the cross-bottom bag that has been developed by turning over t-hebottom side covers from the condition in accordance with FIG. 2, and where the corner flaps are directed outwardly;

FIG. 4 shows the cross-bottom bag in accordance with FIG. 3 where the flaps that had extended outwardly have been placed and glued onto the cross-bottom side folds or pleats;

FIG. 5 shows a corner fold of the bottom of the bag in accordance with FIG. 3 to an enlarged scale;

FIG. 6 corresponds to the illustration in accordance With FIG. 5, except that here the corner flap layer located inside is folded over inwardly about the edge of the opening and glued on;

FIG. 7 shows the corner with outwardly folded corner FIG. 10 is a representation in accordance with FIG. 9, but with the corner flaps glued onto the side folds;

FIG. 11 is an enlarged view of a corner flap of a bottom in accordance with FIG. 3 or 5, with an additional welded or glued seam; and

FIGS. 12 and 13 show the arrangement and form of the gluing strip at the opening edge.

A three-layer tubular section 1 as shown in FIG. 1 has an outer layer 2, intermediate layer 3, and an inner layer 4. The layers 5, 6, 7 of the corner flaps 31, 32, 33 in FIGS. 1 and 3, which are formed by the longitudinal incisions 9, 10, 11 in the tube section 1 are not staggered longitudinally of the corner flaps, and of the tube section. The layers at the ends of the corner flaps may, however, be staggered in a known manner.

The incisions 9, 10, 11 are arranged in such a manner that at each longitudinal edge of each corner flap a positive staggering is obtained which is from the inside toward the outside, i.e., the outer layers 6 and 7 cover the inner layer at the longitudinal edges of the corner flaps.

The incisions 9, 10, 11 extend to the lines 12 and 13. The dash and dot lines 14 and 15 represent the subsequent folding lines of the cross-bottom bag. In accordance with FIG. 2, the staggered tube 1 is folded along these lines 14, 15 and at each end of the tubular section 2 triangular bottom corner folds 16, 17, 18, 19 have been formed. Along the folding lines 20, 21, 22, 23 the lateral folds 27, 28, 29, 30, in accordance with FIG. 3 are turned over after the triangles 24, 25, 26 have been turned out. In this manner, multi-l-ayer flaps 31, 32, 33 (FIG. 3) are formed, to which has been imparted the positive staggering transversely of the longitudinal direction of the bottom due to the incisions 9, 10, 11. At the corner opposite of the corner flap 33, no fold is provided. This corner serves for accommodating the valve. In the valve channel 34, any desired type of valve may be accommodated.

In accordance with FIG. 4 the corner flaps 31, 32, 33 are folded over along the folding edges 35, 36, 37 which register with the transverse corner fold edges and are glued onto the bottom flaps 27 and 29.

In FIG. 5 the corner fold of the bottom with the corner flap 33 in accordance with FIG. 3 is shown to an enlarged scale for the sake of clearer illustration.

In accordance with a further embodiment of the invention, the inner corner flap position 5 is in accordance with FIG. 6 folded. over and glued along the proximate edge 39 of the opening edge of the inner layer 3 of the bottom side folds at the end points b of the incisions 10. This is followed by a further folding of the corner flap layer 5 about the folding edge 37 as illustrated in FIG. 4.

FIG. 7 illustrated a further embodiment of a corner of such a bag, where a cover strip 40 is glued over the outer corner flap 33. The cover strip 40 has a width corresponding to the width of the outermost corner flap layer 33 and the length of this cover strip is so chosen that it sufficiently covers the edges 41, 42, 43 at the opening edges at both sides. Since two cover strips would be necessary at each cross-bottom with this embodiment, these two cover strips can also be replaced by a longitudinal strip of suitable length.

FIG. 8 of the drawing shows how the outwardly directed corner flap 33 in accordance with FIG. 7 and the cover strip 40 are placed inwardly and glued onto the closed side folds or pleats.

FIG. 9 shows in connection with a further embodiment a corner of a conventional bag tube 44 in nonstacked execution with the corner flap 45. This tube has incisions, the end points 47, 48 of which determine the connecting line 46. The corner flap 45 is covered by the cover strip 49 which is of importance here. The length of this cover strip 49 corresponds to the width of the bottom. As reflected by FIG. 10 in connection with FIG. 9, the corner flaps 45 are folded over along the line 37, i.e., the transverse edge of the associated corner fol and glued on. Subsequently, a conventional closure leaf can still be applied, whereupon further gluing of the endangered discharge points 47, 48 is effected.

If such a bag in accordance with the foregoing description, and as illustrated in the embodiments of the drawing is made with an inner layer of coated paper, then it is suitable in accordance with FIG. 11 to close this inner layer by means of a welding line 50 whereby an improved absolutely sealed closure is provided. This welding seam may also be obtained by means of a suitable deposit of a agglutinative.

In FIG. 12 the arrangement of a glue strip 52 on one of the corner flaps is illustrated which, in this case, is the corner flap 32 that is adjacent to the edge 51 of the opening 0. By this means, a closure is also provided at the ends 9b of the edge 9a produced by the longitudinal incision 9 in the innermost layer. It is still more advantageous as shown in FIG. 13 to arrange the glue strip 53 at both sides of the edge 51. The further securing of the remaining sections of the corner flaps with the side folds 27, 28 is independent of the arrangement of the glue strip in the manner mentioned. The remaining sections may likewise be provided entirely, or only partly with glue, and glued onto the side folds.

As illustrated by the preferred embodiments of the subject of the invention illustrated in the drawing, the corner flaps are not stacked in the longitudinal direction of the bottom of the bag. In this manner the very undesirable staggering which otherwise is unavoidable at one end of the bottom is avoided.

Having now described my invention with reference to the embodiments illustrated in the accompanying drawings I do not wish to be limited thereto, but what I desire to protect by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. Multi-layer cross-bottom bag of paper or the like comprising at least an inner and an outer tubular layer, each having bottom side folds turned inwardly towards one another and corner flaps formed in each tubular layer proximate the ends of said side folds by longitudinal incisions and adapted to be glued onto the associa-ted inwardly turned side folds, the layers of said cOrner flaps formed by said longitudinal incisions being arranged in positively staggered fashion from the inside layer toward the outside layer.

2. Multi-layer cross-bottom bag in accordance with claim 1, where said side folds define edge folds at the ends thereof :and each corner flap has a base end extending between two edge folds, and two longitudinal edges, and a strip of adhesive substance extends from one longitudinal edge to the other by means of which said corner flaps are glued to said side folds.

3. Multi-layer cross-bottom bag in accordance with claim 2, Where said strip of adhesive substance extends at least onto a part of the side folds.

-4. Multi-layer cross-bottom bag in accordance with claim 1, where said side folds define edge folds at the ends thereof and each corner fiap has a base end extending between two edge folds with the bases of successive layers staggered and where the inward corner flaps are folded about the base line of the next following layer and glued onto the side folds while the remaining layers are folded together along a line between the junction of the side folds and the edge folds.

5. Multi-layer cross-bottom bag in accordance with claim 1, where triangular pockets are formed at the ends of said side folds with a hypotenuse extending between the base of the pocket triangles and a cover strip is placed between the hypotenuse and the base of the corner flap of the inner layer, said strip having a length corresponding to the width of the broadest corner flap.

6. Multi-layer cross-bottom bag in accordance with claim 1, where the innermost flap is provided with a 5 6 welded seam transversely of the end of the cross bottom. References Cited by the Examiner 7. Multi-layer cross-bottom bag in accordance with UNITED STATES PATENTS claim 1, where triangular pockets are formed at the ends of said side folds with a hypotenuse extending between 2,729,150 1/1956 Gelbcke the base of the pocket triangles and a cover strip is 5 placed between the hypotenuse and the base of the corner FOREIGN PATENTS flap of the inner layer, said strip extending across said 1 147 547 57 Rama corner flaps and having a length corresponding to the Width of the cross bottom, one edge of said strip being JOSEPH R, LECLAIR, Primary Examiner.

proximate said hypotenuse and said flaps and strip being 10 folded around said hypotenuse. D. M. BOCKENEK, Asszstant Examiner. 

1. MULTI-LAYER CROSS-BOTTOM BAG OF PAPER OR THE LIKE COMPRISING AT LEAST AN INNER AND AN OUTER TUBULAR LAYER, EACH HAVING BOTTOM SIDE FOLDS TURNED INWARDLY TOWARDS ONE ANOTHER AND CORNER FLAPS FORMED IN EACH TUBULAR LAYER PROXIMATE THE ENDS OF SAID SIDE FOLDS BY LONGITUDINAL INCISIONS AND ADAPTED TO BE GLUED ONTO THE ASSOCIATED INWARDLY TURNED SIDE FOLDS, THE LAYERS OF SAID CORNER FLAPS FORMED BY SAID LONGITUDINAL INCISIONS BEING ARRANGED IN POSITIVELY STAGGERED FASHION FROM THE INSIDE LAYER TOWARD THE OUTSIDE LAYER. 